Decline in Americans' belief in global warming

For the past decade, researchers have been studying what Americans believe about climate change.

For several years, more and more of the public has agreed that climate change is taking place. But recently, the number of people who believe climate change is happening is falling.

I talked with Barry Rabe, a professor in the Gerald R. Ford School of Public Policy at the University of Michigan.

He’s the author of a new report that draws on the latest public opinion surveys.

Here's what he had to say about the report, which found fewer people believe the Earth is warming:

"We found in the United States as well as in Michigan that there appears to be an upward trajectory of this in the past decade. Do you think global temperatures are warming, independent of the question of human causation, and other questions about perceptions of global warming consistently increasing, probably peaking in late 2008.

Since that time in the United States, we’ve seen a drop of about 18-20 percentage points on some of the very basic, standard survey questions that have been used for some time in the U.S. and really around the world.

In our latest survey which comes from November 2010, we actually see a little bit of bouncing back up again, not back to those November 2008 levels but for our purposes what this suggests is public understanding and perception of climate change is really a pretty volatile area of public opinion.

The numbers move around quite a bit from year to year, much more than we would have ever anticipated."

He thinks one main reason why belief in global warming has dropped over the past couple years is because a lot of people are affected by the weather in their own backyards.

"We think to some extent, all climate interpretation is local. When we ask people where they get information about climate and how they begin to think about these issues, overwhelmingly the way they respond is to talk about their own experience with weather. How has the last year been, has it been a cooler year, a warmer year, have they seen evidence? If you ask this question in different parts of the country, you might get very different answers. In California, perception of climate change is all related to drought. Go to Mississippi or Louisiana, it’s all about hurricanes. It’s part of the challenge of climate change, it means different things in different parts of the world, including here in Michigan. But invariably that’s influenced by where people get their information, from meteorologists, what television they watch, who they listen to in terms of expert authorities, all these kinds of issues. And of course over this period in which there has been this shift or downward movement in concern about climate change, there have been a number of controversies over certain aspects of science, the so-called “Climate Gate” controversy. We actually noticed a substantial drop in that very period where there were some leaked emails and questions about the rigor of some of the climate science that was very influential in the UN process. That seemed to contribute at least in some way."

I asked him if he also found less support for policies that would take action on climate change:

"Speaking very generally, Michiganders and Americans tend to believe, majorities in each areas, that federal and state and local governments should be devoting some attention to this issue. One particular policy, so-called cap and trade, which of course was the center point of discussions in the last Congress, in 2009 and 2010, for possible federal legislation, we have seen some shift and movement on that, less support than we saw a few years ago, but many of the other policy interventions have not shifted all that significantly."